As a coding method that enables compression coding at least twice as efficiently as H.264, there is high efficiency video coding (HEVC). HEVC is a basic technology for broadcasting, distributing, and accumulating next-generation 4K and 8K images. Furthermore, in transmitting, distributing, and accumulating images of quality less than or equal to full high-definition (HD) quality, HEVC enables increases in the quality of the images and in the number of channels.
In H.264, a macroblock (MB) that is a fixed image region of 16×16 pixels is a basic unit of encoding processing. Contrarily, in HEVC, a coding unit (CU) that has a hierarchical quad-tree structure and is variable between 8×8 pixels and 64×64 pixels, and a prediction unit (PU) or a transform unit (TU) are each a basic unit of encoding processing. Thus, in HEVC, a unit of encoding processing is adaptively and hierarchically determined, thereby increasing compression coding efficiency.
Related art is disclosed in Japanese Laid-open Patent Publication No. 2014-204207.